Question

Find the mean, variance, and standard deviation of the sample with

n = 10 , ∑x = 210 and ∑x² = 5006

Use the given information above to find:
Mean =
Variance = (round the result to one decimal place)
Standard Deviation = (Round the result to one decimal place).

Please help!

Answer 1

Mean:-

`\\ \tt\hookrightarrow (\sum x)/(n)=(210)/(10)=21`

Standard Deviation:-

`\\ \tt\hookrightarrow \sqrt{(\sum x^2)/(n)-(\sum x/n)^2}`

`\\ \tt\hookrightarrow \sqrt{(5006)/(10)-(21)^2}`

`\\ \tt\hookrightarrow √(500.6-441)`

`\\ \tt\hookrightarrow √(59.6)`

`\\ \tt\hookrightarrow 7.72`

Variance:-

`\\ \tt\hookrightarrow (S. D)^2=(7.72)^2=59.6`